DHCP server not fonction with Meraki C9300X-24Y-M

[Aysha]

Hi Everyone,

I'm encountering some issues with my C9300X-24Y-M switch. When we configure a port in access mode, the endpoint connected to that port does not receive an address from the DHCP server configured on the Meraki dashboard. Instead, it receives an IP address from the network where the uplink (the port providing internet access for communication with the dashboard) is connected.

We have tried configuring the uplink port as both access and trunk, but the issue persists.

Additionally, we are fully compliant with licensing requirements.

Any insights or suggestions would be appreciated.

[Shubh3738]

Check VLAN settings on the C9300X-24Y-M switch.

Ensure access ports are assigned to the correct VLAN.

Verify trunk port settings allow the necessary VLANs.

[Aysha]

thanks, already done

[Shubh3738]

Have you tried cycling the port after making the configuration changes?

Additionally, if you manually assign an IP address to the endpoint, does it successfully connect to the network?

[Aysha]

If i configure manually 2 endpoints in the same vlan, they can ping each other but they cannot ping their svi. 

[cmr]

You definitely have a VLAN issue then, unless you have firewall rules blocking ICMP.  I'd guess that your port VLANs and SVIs aren't matching up.

[Aysha]

Hi, no rules blocking icmp actually. But I was wondering to know if ever there were some issues with vlan IDs greater then 1000, because when I changed the vlan Id, of the the vlan 1213 to 100, the dhcp assignment is working fine. And when I want to put a port in access to the vlan 1213 I have errors as you can see below.

But I red somewhere that the issue can be in the management vlan side… This is my first in Meraki but I’m already missing CLI lol.

[cmr]

On the C9300 you can only have 1000 VLANs defined.  You can have VLAN IDs greater than 1000 but you must then change all the 1-1000 entries that you see on trunk ports to 1-100,150-200,1000-1400 etc. where the total across all locations is up to but not more than 1000.

[PhilipDAth]

For the access mode port, what VLAN number did you configure?

Which VLAN is the upstream DHCP server in?

Is the port between this switch and the upstream switch configured as a trunk port with the same native VLAN?

[Aysha]

I tried to put the port in different vlan but it was the same issue all the time. As mentionned in One of my replies, when I changed the vlan Id of the the vlan 1213 to 100, the dhcp assignment is working fine. And when I want to put a port in access to the vlan 1213 I have errors as you can see below.

 Regarding the upstream port it is now configured in access, but before it was in trunk vlan 1 because it’s just connected to an independent network which can give access to the internet different from the network of the customer.

[AlexL1]

Hi Aysha,

As the warning/alert is stating "the switch is limited to 1000 VLANs" while you seem to have VLANs 1, 10, 16, 1213, and a range between 1-1000 in your network
--> The Catalyst 9300 switches ships with VLANs 1-1000 active.
Therefore using VLAN=1213 would not work since it's not in the active VLANs range between 1 - 1000.

There is a new feature called "VLAN Database" which provides a simple way to remove, or prune any VLANs that are not needed from the switch's VLAN database and allows for a single place to configure the entire VLAN range needed in the topology and/or the switches attached to a VLAN Profile. This has historically required additional effort on a switch by switch basis to modify.

This has historically required additional effort on a switch by switch basis to modify. The error that could be observed by this condition is: "Combined count of Allowed VLANs and Native VLAN cannot exceed 1000 VLANs".

This feature is limited to Cloud Managed Catalyst switches only. This feature does NOT effect how MS Classic series switches function.

https://documentation.meraki.com/General_Administration/Cross-Platform_Content/VLAN_Profiles

If you have any further questions, please don't hesitate to contact us.

[Aysha]

Hi Alex,

Thank you for your reply, i don't have the active vlans option, and in the interface configuration i don't have any dropdown menu. At the beginning i saw that some features are not working for the catalyst-M switches so i thought it was my case, but now i'm little bit confused. Find attached the screenshots.

[AlexL1 · Accepted solution]

Hi Aysha,

Thank you for sending screenshots.

Is your main goal to add VLAN=1213 to the Active VLAN Database?

Please check below.

VLAN profiles is supported on the following platforms and firmware versions:

Platform Family

Model

Minimum Firmware

Catalyst C9K-M

C9K-M

CS16+/Cloud Native IOS XE

Have you enabled VLAN Database feature by navigating to Organization --> Early Access --> VLAN Database Opt-in?

The VLAN Database feature provides a simple way to remove, or prune any VLANs that are not needed from the switch's VLAN database and allows for a single place to configure the entire VLAN range needed in the topology and/or the switches attached to a VLAN Profile. This has historically required additional effort on a switch by switch basis to modify. 

The VLAN Database is a function of VLAN profiles, which can be applied to individual or groups of switches. An example would be if you use the same VLANs across many switches in a network, a single VLAN profile can often be used to limit the active VLANs.

This feature is limited to Cloud Managed Catalyst switches only. This feature does NOT effect how MS Classic series switches function.

In conclusion, in your case the default Active VLANs for the Catalyst 9300 are between 1 - 1000.

Therefore, if you would like to use VLAN=1213, you will have to use Prune function.

Example, Active VLANs 1-999, and 1213 --> That way you will remove VLAN=1000 from the VLAN DB.

https://documentation.meraki.com/General_Administration/Cross-Platform_Content/VLAN_Profiles#VLAN_Da...

If you have any further questions, please don't hesitate to contact us 🙂

Note: If a user configures a VLAN on an access port that is NOT in the Active VLAN list, IOS XE will auto instantiate that VLAN. Dashboard will remove/prune that VLAN within and hour for IOS-XE devices but NOT for devices running CS Firmware.

[Aysha]

Dear team,
We finally solved this dhcp issue by activating the features of vlan database and vlan profiles in early access, then configured the range of vlan we need on active vlans, and from there it seems that everything is working fine so far, we can even put a port in access 1213, we are observing since yesterday.
Thank you all for your feedback and help.